The present invention relates to microfabricated fluidic systems and methods for regulating the flow of fluid to provide switches, logic gates, latches, pressure sources, analog devices, capacitors, unidirectional valves, pressure multipliers, and devices that perform mathematical functions.
Microfabricated fluidic chips may be used for biological assays. For example, microfabricated fluidic chips may be used to perform biological assays using external control lines that control the opening and closing of on-chip fluidic valves. The on-chip fluidic valves control the flow of fluids in biological assays. The valves are opened and closed using macroscopic pressure sources that are located off-chip, and which are connected through control lines to the chip. In complex assays, a large number of macroscopic control lines is cumbersome and undesirable. Previously known electrical actuating devices have not been able to provide sufficient force by themselves to open or close a fluidic valve.
It would therefore be desirable to provide pressure sources and control lines on-chip that control the opening and closing of on-chip valves so that macroscopic control lines exiting the chip are minimized or eliminated. Previously known on-chip systems have not been adequate to provide control of numerous on-chip valves. Each valve requires a pressure differential between the input and the output to control the valve. Numerous valves coupled together to perform complex functions would require very large pressure differentials to drive all of the cascaded valves. Pressure sources that generate such very high pressure differentials are difficult to manufacture on a microfabricated chip.
Furthermore, such cascaded valve systems do not allow for the introduction of feedback elements. A feedback element is one whereby a (downstream) output pressure, which is controlled by an upstream valve or is controlled by a valve which is controlled by the upstream valve (and so on), in turn controls the function of the upstream valve. The elimination of the possibility of feedback precludes the construction of entire classes of analog devices and digital logic devices (e.g., latches).
It would also be desirable to provide numerous microfabricated fluidic switches on-chip that open and close channels without the need for large pressure differentials.
It would also be desirable to provide devices that perform logic functions, signal latching, mathematical functions, and other complex functions on-chip.
It would also be desirable to provide microfabricated fluidic switches on-chip that incorporate the feed back of information from a downstream part of the circuit to an upstream part.
It is therefore an object of the present invention to provide pressure sources and control lines that control the opening and closing of valves on-chip so that macroscopic control lines exiting the chip are minimized or eliminated.
It is also an object of the present invention to provide numerous microfabricated fluidic switches on-chip that open and close channels without the need for large pressure differentials.
It is also an object of the present invention to provide devices that perform logic functions, signal latching, mathematical functions, and other complex functions on-chip.
It is also an object of the present invention to provide microfabricated fluidic switches on-chip that incorporate the feed back of information from a downstream part of the circuit to an upstream part.
The present invention sets forth systems and methods for designing and operating microfabricated fluidic (i.e., microfluidic) devices such as switches, logic gates and latches (e.g., flip-flops) that provide control signals which can be fabricated on microfluidic chips. The microfluidic switches, logic gates, and latches of the present invention may operate entirely on-chip without the need for off-chip pressure sources.
The present invention also provides on-chip pressure sources that can drive the microfluidic switches, logic gates and latches. The present invention also provides on-chip microfluidic unidirectional valves, capacitors, switching regulators, and pressure multipliers, that are formed with elastomer material that can also operate without off-chip pressure sources. The devices and methods of the present invention control and channel fluid movement on-chip to perform a variety of functions.
Microfabricated fluidic devices of the present invention may be configured to imitate the functionality of semiconductor circuits, such as ON/OFF switches, capacitors, logic gates, latches, switching regulators, and devices that perform mathematical functions. The microfabricated fluidic logic gates of the present invention include AND gates, OR gates, NOR gates, NAND gates, inverters, and numerous other Boolean and logic functions. The logic functions performed by the microfabricated fluidic devices may also be configured to perform mathematical functions such as addition, subtraction, multiplication, and division.
Microfabricated fluidic (i.e., microfluidic) devices of the present invention may also perform analog functions such as amplification or regulation. For example, devices of the present invention include switching regulators, capacitors, pressure multipliers, and pressure sources. Other analog functions may also be performed using microfluidic devices of the present invention.